Niraparib 是一种选择性 PARP1/PARP2 抑制剂，IC50分别为 3.8 nM 和 2.1 nM。它抑制 DNA 损伤修复，诱导凋亡并具有抗肿瘤活性。

MK-4827(Niraparib) is a selective inhibitor of PARP1/PARP2 with IC50 of 3.8 nM/2.1 nM; with great activity in cancer cells with mutant BRCA-1 and BRCA-2; >330-fold selective against PARP3, V-PARP and Tank1.

In a whole cell assay, MK-4827 inhibited PARP activity with EC50 = 4 nM and inhibited proliferation of cancer cells with mutant BRCA-1 and BRCA-2 with CC50 in the 10-100 nM range. It was demonstrated to be a potent and selective PARP-1 and PARP-2 inhibitor with IC50=3.8 and 2.1 nM, respectively. Furthermore, it displayed at least a 100-fold selectivity over PARP-3, V-PARP, and tankyrase-1, with IC50 = 1300, 330, and 570 nM, respectively. As well as inhibiting the growth of HeLa cell lacking BRCA-1 because of silencing by RNA interference, MK-4827 is able to inhibit the proliferation of cancer cell lines carrying natural BRCA-1 or BRCA-2 mutations. In MDA-MB-436 human mammary gland adenocarcinoma cells carrying BRCA-1 mutations, MK-4827 displayed CC50 = 18 nM, while in CAPAN-1 human pancreatic adenocarcinoma cells, which are BRCA-2 mutant, MK-4827 displayed CC50 = 90 nM. In contrast, normal human prostate and mammary epithelial cells are resistant to MK-4827, displaying antiproliferative effects in the micromolar range, thereby demonstrating the very high selective cytotoxicity from these PARP inhibitors in BRCA-1 and -2 mutant cancer cells compared to surrounding tissue[2].

MK-4827, a novel, orally bioavailable, PARP-1 and PARP-2 inhibitor, strongly enhanced the effect of radiation on a variety of human tumor xenografts, both p53 wild type and p53 mutant[1]. It was well tolerated in vivo and demonstrated efficacy as a single agent in a xenograft model of BRCA-1 deficient cancer[2].

Enzyme assay is conducted in buffer containing 25 mM Tris, pH 8.0, 1 mM DTT, 1 mM spermine, 50 mM KCl, 0.01% Nonidet P-40, and 1 mM MgCl2. PARP reaction contains 0.1 μCi [3H]NAD+ (200?000 DPM), 1.5 μM NAD+, 150 nM biotinylated NAD+, 1 μg/mL activated calf thymus, and 1?5 nM PARP-1. Autoreactions utilizing SPA bead-based detection are carried out in 50 μL volumes in white 96-well plates. Compounds (e.g., MK-4827) are prepared in 11-point serial dilution in 96-well plate, 5 μL/well in 5% DMSO/Water (10× concentrated). Reactions are initiated by adding first 35 μL of PARP-1 enzyme in buffer and incubating for 5 min at room temperature and then 10 μL of NAD+ and DNA substrate mixture. After 3 h at room temperature, these reactions are terminated by the addition of 50 μL of streptavidin-SPA beads (2.5 mg/mL in 200 mM EDTA, pH 8). After 5 min, they are counted using a TopCount microplate scintillation counter. IC50 data is determined from inhibition curves at various substrate concentrations[1].

Proliferation assays were conducted in 96-well black viewplates, and 300 cells/well (250 cell/well for BRCA-1 wt) in culture medium, 190 μL/well (DMEM containing 10% FCS, 0.1 mg/mL penicillin-streptomycin, and 2 mM L-glutamine), were plated and incubated for 4 h at 37℃ under 5% CO2 atmosphere. Inhibitors were then added with serial dilutions, 10 μL/well to obtain the desired final compound concentration in 0.5% DMSO. The cells were then incubated for 7 days at 37℃ in 5% CO2 after which time viability was assessed. Briefly, with CellTiter-Blue solution prediluted 1:10 in medium, 100 μL/well was added and the cells left for 45 min at 37℃ under 5% CO2 and then a further 15 min at room temperature in the dark. The number of living cells was determined by reading the plate at fluorimeter, excitation at 550 nm and emission at 590 nm. Cell growth was expressed as the percentage growth with respect to vehicle treated cells. The concentration required to inhibit cell growth by 50% (CC50) was determined.(Only for Reference)

1038915-60-4

C19H20N4O

320.39

尼拉帕尼;MK-4827

Ethanol:60 mg/mL (187.3 mM)
H2O:<1 mgml
DMSO:60 mg/mL (187.3 mM)
Powder: -20°C for 3 years
In solvent: -80°C for 2 years